Paper discharge device

Abstract

When a face of a paper sheet to be discharged on which an image is formed faces downward, a paper discharge device divides an image region of image data on the paper sheet to be discharged into areas along a discharge direction, detects an area in which maximum image density for each divided area is higher than or equal to a specified threshold, and controls a discharge angle so that the detected area does not come into contact with a stacked paper sheet until the paper sheet to be discharged has been discharged from a discharge roller.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2014-111914, filed on May 30, 2014, the entire contents of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The embodiments discussed herein are related to a technique for preventing deterioration in image quality due to rubbing between paper sheets with respect to a paper discharge device.[0004]2. Description of the Related Art[0005]With respect to a paper discharge device, various techniques have been developed for preventing misalignment of discharged paper sheets when paper sheets are stacked. When contact between a paper sheet and a discharge roller is released and the paper sheet is discharged in a not-in-contact state with stacked paper sheets, since the paper sheets fall freely and reach the stacked paper sheets, alignment of discharged paper sheets deteriorates. Th...

AI Technical Summary

Benefits of technology

This patent text is directed to a problem where staining is generated during paper discharge due to rubbing of a print image. The invention provides a paper discharge device that prevents quality degradation of printed matter due to rubbing. By placing a high-density area on a paper sheet to be discharged so that it does not rub the back face of a stacked paper sheet, the discharge angle is set so that the high-density area does not contact the back face. This results in a discharge device that prevents staining and maintains image quality.

Problems solved by technology

By adopting a configuration for bringing a paper sheet to be discharged into contact with stacked paper sheets, paper sheet alignment may be stabilized by preventing scattering of paper sheets to be discharged; however, there arises a problem in which staining is generated by rubbing a print image due to contact during discharge.

In particular, when a portion with a high image density on a paper sheet is rubbed, it is more likely to generate staining.

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